1-2 How the FISH 4500/4600 works
The FISH 4500/4600 has two parts:
-the transducer attached to the hull
-the display unit.
The transducer generates an ultrasonic pulse (sound that is above the hearing range of the human ear), which travels down towards the bottom at a speed of about 4800 ft/sec (1463 m/ sec), spreading out into a cone shape.
When the pulse meets an object, such as a fish or the bottom, it is partly reflected back up towards the boat as an echo. The depth of the object or bottom is calculated by the FISH 4500/4600 by measuring the time taken between sending a pulse and receiving the echo. When an echo has been returned, the next pulse is sent.
The FISH 4500/4600 converts each echo into an electronic signal, displayed as a vertical line of pixels. The most recent echo appears on the extreme right of the display, with the older echoes being scrolled towards the left, eventually disap- pearing off the display.
The scroll speed depends upon the water depth and scroll speed setting. See section
>Sonar and section
The appearance of echoes displayed are af- fected by:
•the fishfinder settings (frequency selected, range and gain settings)
•echoes (different fish types, different bot- tom types, wrecks and seaweed)
•noise (water clarity and bubbles).
See section
FISH 4500/4600 Installation and Operation Manual | NAVMAN | 5 |
